Performance characterization of micromachined particle separation system based on Zweifach–Fung effect

Integration of separation has always been a challenge in a microfluidic system. Human blood tests in clinical diagnostics often require cell-free samples in order to provide adequate sensitivity of measurements.This article characterizes the performance of microfluidic test structures utilizing the Zweifach–Fung effect in terms of two performance metrics: separation and purity efficiency. A series of silicon–glass based microfluidic chip were designed and fabricated by conventional MEMS technology. The influence of geometric parameters of several bifurcation arrangements was quantitatively analyzed under different flow conditions. Finite element modeling of the fluid flow in the vicinity of the bifurcations is also implemented to help the understanding of the experimental results.Our work contributes to optimal geometric design of separation components of microfluidic based diagnostic chips.